Hao MY, Huang MH, Gu XY, Zhang TS, Zhu XT, Hao WJ, Jiang B. Diastereoselective Generation of C
2-Azlactonized 2
H-Chromenes via Brønsted Acid-Catalyzed Oxo-Cyclization of Propargyl Alcohols.
J Org Chem 2022;
87:1518-1525. [PMID:
35000383 DOI:
10.1021/acs.joc.1c02299]
[Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A new Brønsted acid-catalyzed oxo-cyclization of propargyl alcohols with azlactones to synthesize C2-azlactonized 2H-chromenes has been established that uses 1,1'-binaphthyl-2,2'-diyl hydrogen phosphate (BiNPO4H) as the catalyst and gives excellent diastereoselectivities (≥19:1 dr) in most cases. This protocol has a high compatibility with various substituents of substrates, offering a catalytic and useful entry to the fabrication of the synthetically important C2-functionalized 2H-chromene scaffold.
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